This invention relates to a method of protecting both human and animal endothelial and epithelial cells which are subject to exposure to trauma. More particularly, this invention concerns protecting endothelial and epithelial cells in anticipation of surgical trauma using chondroitin sulphate.
Since human corneal endothelial cells are not known to reproduce, it is of vital importance to protect endothelia to prevent cell damage prior to subjection to inticipated trauma, such as surgery. Recent advances in corneal endothelial cells subject to irreversible destruction during such surgery. Of particular significance is the need to protect corneal endothelial cells during intraocular lense (IOL) implantation corneal transplantation and other intraocular surgical operations. Previous work in this field has been directed to protecting corneas with both non-biological and biological polymers.
Macromolecules heretofore employed in the protection of corneas prior to surgery include bovine serum albumin, human gamma globulin, hyaluronic acid and polyvinylpyrrolidone. The use of sodium hyaluronate as an aid in ophthalmic surgery is described in "HEALON" Product Monogram, Pharmacia Laboratories, Piscataway, N.J., 1980.
The employment of the aforementioned biological macromolecules has not met with complete satisfaction due to insufficient cell protection, i.e. significant corneal endothelial cell damage, and the onset of significant complications caused by some of these biological polymers. Sodium hyalurate, for example, is known to cause temporary glaucoma.
The therapeutic qualities of hyaluronic acid to aid wound healing have been previously reported by E. A. Balasz and D. A. Gibbs in "The Rheological Properties and Biological Function of Hyaluronic Acid", Academic Press (New York), 1970. Ultrapure hyaluronic acid and the use thereof is the subject of U.S. Pat. No. 4,141,973 to E. A. Balasz. Furthermore, it has been shown that sulphated mucopolysaccharides have a greater deturgescence effect on the cornea and that viable corneal stroma incorporate sulphur from a bath containing sulphate. See M. E. Langham, "Macromolecular Organization Of A Connective Tissue", Johns Hopkins Press, 1968; J. A. Capella, H. F. Edelhauser, D. L. Van Horn, "Corneal Preservation", Charles C. Thomas Publisher, 1973.
U.S. Pat. No. 3,211,616 of Zensaku Yosizawa concerns N,O-sulphated neutral-mucopolysaccharides.
U.S. Pat. No. 1,950,100 of Lathan A. Crandall relates to chondroitin compounds and their preparation. Crandall discloses that chondroitin is suitable for the treatment of such diseases as migraine, urticarial eruptions, peptic ulcers, multiple sclerosis, allergies and hepatic cirrhosis.
It is known that chondroitin sulphates are effective in preventing the development and evolution of some types of complicated lesions in atherosclerosis. Also the chondroitin sulphates exhibit a marked increase during various injuries to the arterial wall.
In view of the above, it would thus be advantageous to have a method which would afford significant cell protection during surgery and concomitantly be relatively free from contraindications.